feat: enhance blog and SEO features with new plugins and metadata

- Introduced rehypeLazyImages plugin for lazy loading images in blog posts.
- Updated sitemap integration to include last modified dates for blog posts.
- Enhanced Head and BaseLayout components to support additional Open Graph metadata.
- Improved RSS feed generation with sanitized content and author information.
- Updated manifest.json for a darker theme and standalone display mode.
- Added support for language-specific attributes in various components.
- Refactored blog post handling to include modified and published timestamps.

public/manifest.json

@@ -18,7 +18,7 @@
       "type": "image/png"
     }
   ],
-  "background_color": "#ffffff",
-  "theme_color": "#ffffff",
-  "display": "fullscreen"
+  "background_color": "#181818",
+  "theme_color": "#181818",
+  "display": "standalone"
 }